Combustion promoter for internal combustion engines

ABSTRACT

A combustion promoter for an internal combustion engine comprising a cylinder having a combustion chamber therein, a main piston movable within the cylinder, a sub-piston mounted on an inner wall of the main piston, and a sub-cylinder surrounding the projecting portion of the sub-piston and defining a sub-cylinder chamber. The sub-piston is driven in relation to the stroke of the main piston toward the combustion chamber until the main piston has reached a position in the vicinity of top dead center of a compression stroke. Gas in the combustion chamber is then introduced into the sub-cylinder chamber where it is stored. The sub-piston is next moved rapidly away from the combustion chamber to eject the gas stored in the sub-cylinder chamber into the combustion chamber, thereby promoting combustion of the gas.

BACKGROUND OF THE INVENTION

This invention relates to a device which promotes firing in internalcombustion engines. More specifically, it relates to a device whichpromotes firing in the cylinders of internal combustion engines such asgasoline and diesel engines.

There are known devices which promote firing in internal combustionengines by providing an orifice system which intakes a uniformpreviously mixed fuel and air mixture through openings in an inside wallof a cylinder. Swirl is thereby produced during the intake stroke.However, the opening and closing mechanism is complicated anconsequently an effective swirl is not obtained before firing has begun.

This invention provides a comparatively simple device which promotesfiring to produce swirl at the beginning of firing in the combustionchamber of an internal combustion engine.

SUMMARY OF THE INVENTION

The present invention is a combustion promoter for an internalcombustion engine which comprises a cylinder having a combustion chambertherein, a main piston movable within the cylinder, a sub-piston mountedon an inner wall of the main piston, and a sub-cylinder surrounding aprojecting portion of the sub-piston and defining a sub-cylinderchamber. The sub-piston is driven in relation to the stroke of the mainpiston toward the combustion chamber until the main piston has reached aposition in the vicinity of top dead center of the compression stroke.Gas in the combustion chamber is then introduced into the sub-cylinderchamber where it is stored. The sub-piston is next moved rapidly awayfrom the combustion chamber to eject the gas stored in the sub-cylinderchamber into the combustion chamber, thereby promoting combustion of thegas.

Ejection of the gas stored in the sub-cylinder chamber causes a swirl tooccur in the gas which has just started combustion. Consequently, firingeffects are improved remarkably.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a first embodiment of a cylinder ofan internal combustion engine constructed in accordance with thisinvention;

FIG. 2 is a top view of the pistons incorporated in the engine of FIG.1; and

FIG. 3 is a sectional view showing a second embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a first embodiment of my invention wherein 1 is a cylinderwall, 2 is a cylinder head, 3 is a cylinder chamber, 4 is a combustionchamber, 5 is a main piston, 6 is a gas saving blasting device, 7 is asub-piston of the gas saving blasting device 6, 8 is a piston rod of thesub-piston 7, 9 is a piston rod guide for the sub-piston 7, 10 is an oildamper, 10' is a small hole in the bottom part of the oil damper, 11 isa spring plate, 12 is a support for the spring plate, 13 is asub-cylinder wall of the blasting device 6, 6' is a sub-cylinder chamberdefined by the sub-piston 7 and the sub-cylinder wall 13, 14 is aclearance between the sub-piston 7 and the sub-cylinder wall 13, 14'(FIG. 2) is a plurality of small holes in a face 20 of the sub-piston 7,15 is a connecting rod, 16 is a piston pin, 17 is a piston pin holder ofthe connecting rod, 18 is a cam, 19 is the back face of the cam 18, 21is a back face of the sub-piston 7, 23 is an oil damper compressionchamber, 24 is a spherical face of the sub-piston rod 8, 25 is a springinterposed between the inside upper wall of the main piston 5 and thehead of the sub-piston rod 8, 26 is a cavity within the sub-piston rod,27 is an inlet valve of the combustion chamber 4, 28 is an exhaust valveof the combustion chamber 4, 29 is an intake opening, and 30 is anexhaust opening.

The embodiment of my invention shown in FIGS. 1 and 2 operates asfollows. When the main piston 5 reaches a position in the vicinity oftop dead center of the compression stroke, the cam 18 mounted on thepiston pin holder 17 and which is synchronized with the stroke of themain piston, pushes the head 24 of the sub-piston rod 8 in the upwarddirection, via the spring plate 11, against the force exerted by spring25. This causes the sub-piston 7 to rise into the combustion chamber 4when the main piston 5 reaches top dead center. Consequently, a thinmixture of air and gas is introduced into the sub-cylinder chamber 6'through clearance 14 where it is entrapped before and after the mainpiston reaches top dead center due to the action of connecting rod 15.

When firing takes place, the sub-piston rod 8 and sub-piston 7 aresuddenly moved downward assisted by the force exerted by spring 25. Thismotion forces the gas stored in the sub-cylinder chamber 6' through theholes 14' in the face 20 of sub-piston 7 and the clearance 14 intocombustion chamber 4 thereby causing a swirl in the gas which has juststarted combustion. Sub-piston 7 is then moved upward into sub-cylinder13 by the difference in pressure between that in the sub-cylinderchamber 6' and on the back face 21 of the sub-piston 7.

The cavity 26 within the sub-piston rod 8 reduces the weight ofsub-piston 7 permitting rapid upward movement of the sub-piston.Movement of the oil damper 10 during the return trip causes lubricatingoil to be mixed with air in the cylinder chamber 3 and reduce the shockinherent in the return motion. Moreover, lubricating oil from thecompression chamber 23 is forced under pressure by the oil damper 10through the clearance between the rod 8 of the sub-piston 7 and theguide 9.

FIG. 3 illustrates a second embodiment of the invention. In FIG. 3, 1ais a cylinder block, 2a is a cylinder head, 3a is a cylinder, 4a is amain piston , 5a is a combustion chamber, 6a is a cam, 7a is asub-piston of a blasting device, 8a is a sub-cylinder chamber of theblasting device, 9a is a rod of the sub-piston, 10a is a guide of thesub-piston, 11a is a rod head of the sub-piston, 12a is a connectingrod, 13a is a piston pin, 14a is a rocker arm, 15a is an orifice forsaving gas, 16a is a spring, 17a is a projection of cam 6a, 18a is theinside wall of sub-cylinder 7a, 19a is a piston ring, 20a is asub-piston surface, 21a is a sub-piston back face and 22a is a coolingchamber. Cam 6a is driven by a separate connecting cam or drive shaft ofthe internal combustion engine.

The embodiment shown in FIG. 3 operates in substantially the same way asthe embodiment shown in FIGS. 1 and 2. Namely, timing is established insynchronism with the main piston 4a. The projection 17a on the cam 6apushes sub-piston 7a into the combustion chamber 5a by means of rockerarm 14a, and the mixing of fuel and air occurs in the sub-cylinderchamber 8a.

Gas under pressure is transmitted to the combustion chamber 5a throughorifice 15a in the sub-cylinder chamber 8a of the blasting device. Uponreaching the before and after upper dead points which includes the upperdead point itself, the projection 17 on cam 6a is suddenly effected,sub-piston 7a moves into the sub-cylinder chamber 8a by the force ofspring 16a, and gas in the sub-cylinder chamber 8a is forced into thecombustion chamber through orifice 15a thereby producing swirl. In otherforms of this example, the timing of the two sets of cams 6a, 6a can beadjusted to produce swirl more effectively.

As previously mentioned, the gas introduced and saved in thesub-cylinder chamber is blasted into the combustion chamber before andafter the upper dead point including when the upper dead point isreached. As a result, firing in the combustion chamber is remarkablypromoted, strong swirl is produced and firing is obtained at hightemperatures with thin fuel thereby achieving high efficiency, highpressure ratio, lower cost of fuel, and lower public hazard. In a dieselsystem internal combustion engine, strong swirl and an effect similar tothat achieved in gasoline engines is obtained.

I claim:
 1. A combustion promoter for an internal combustion enginecomprisinga cylinder having a combustion chamber therein; a main pistonmovable within said cylinder; a sub-piston mounted on an inner wall ofsaid main piston, said sub-piston having a portion projecting into saidcombustion chamber; and a sub-cylinder surrounding the projectingportion of said sub-piston and defining a sub-cylinder chamber, saidsub-piston being driven in relation to the stroke of said main pistontoward said combustion chamber until said main piston has reached aposition in the vicinity of top dead center of a compression stroke, gasin said combustion chamber being introduced into said sub-cylinderchamber and stored therein, said sub-piston being then moved rapidlyaway from said combustion chamber to eject the gas stored in saidsub-cylinder chamber into said combustion chamber, thereby promotingcombustion of the gas.
 2. A combustion promoter as defined by claim 1which further comprises a connecting rod having a piston pin holder andcam attached thereto, and wherein said sub-piston has a rod driven bysaid cam and an upper face surrounded by said sub-cylinder.